Emmetropic eye growth in East Asians and non-East Asians

Purpose

To compare axial length (AL) growth curves in East Asian (EA) and non-EA emmetropes.

Methods

A meta-regression of 28 studies with emmetrope-specific AL data (measured with optical biometry) was performed. Emmetropia was defined as spherical equivalent refraction (SER) between −0.50 and +1.25 D, determined under cycloplegia if the mean age was ≤20 years. The AL growth curve (mean AL vs. mean age) was first fitted to the full dataset using a weighted nonlinear mixed-effects model, before refitting the model with ethnicity as a two-level grouping variable (EA vs. non-EA). Ethnic differences in growth curve parameters were tested using the Wald test.

Results

A total of 3331 EA and 1071 non-EA emmetropes (mean age: 6.5–23.1 years) were included. There was no evidence of an ethnic difference in either final AL (difference: 0.15 mm, 95% CI: −0.04 to 0.35 mm, p = 0.15) or initial AL, as represented by the amount that the final AL needed to be offset to obtain the y-intercept (difference: −2.77 mm, 95% CI: −10.97 to 5.44, p = 0.51). Likewise, AL growth rate (curve steepness) did not differ between ethnic groups (difference: 0.09, 95% CI: −0.13 to 0.31, p = 0.43). Collectively, AL growth rate decreased from 0.24 mm/year at 6 years of age to around 0.05 mm/year at 11 years of age, after which it dipped below the repeatability of optical biometry (±0.04 mm) and practically plateaued around 16 years of age (final AL: 23.60 mm).

Conclusions

EA and non-EA emmetropes have comparable AL growth curves.     

黄柏及中成药中小檗碱和巴马亭的高效液相色谱法测定

本文以正相高效液相色谱法,用窗口图解技术对色谱条件进行了优化。对黄柏及其中成药中的有效成分——小檗碱、巴马亭的提取、测定条件、标准曲线进行了研究。并对两种含黄柏的中成药样品进行了分析。其中小檗碱的回收率均在97%以上,巴马亭的回收率均在96%以上。     

Adverse reactions to xenon-enhanced CT cerebral blood flow determination

Fourteen institutions performed 1,830 computed tomographic (CT) cerebral blood flow (CBF) examinations with 32% inhaled stable xenon. Respiratory rate delay greater than 10 seconds occurred in 3.6% of patients, with 83% of the delays lasting 10-15 seconds. There was no incident of prolonged respiratory difficulty. Headache (0.4%), seizures (0.2%), nausea and vomiting (0.2%), and change in neurologic status (0.1%) were uncommon, and there were no transient ischemic attacks. The CT CBF method with 32% inhaled stable xenon is thus associated with an acceptably low incidence of adverse reactions.     

Effects of blood loss and fluid volume replacement on serum and tissue gentamicin concentrations during colorectal surgery

BACKGROUND: The prophylactic administration of antimicrobial agents to surgical patients has become standard practice to minimize the risk for postsurgical infection. During surgery, factors such as renal clearance, fluid administration, and blood loss contribute to drug concentrations achieved in the blood and tissues. The aminoglycoside gentamicin was chosen to investigate these factors because it is used for standard antimicrobial prophylaxis in colorectal surgery. OBJECTIVE: The aim of this study was to investigate the effects of surgical blood loss and fluid volume replacement on gentamicin concentrations in serum and in 3 tissue types (subcutaneous fat, epiploic fat, and colonic wall) in patients undergoing colorectal surgery. METHODS: This uncontrolled, open-label study was conducted at the Aretaieion Hospital (Athens, Greece) between November 2002 and March 2003. Patients selected for this study were scheduled to undergo elective colorectal surgery of ? 2-hour duration with general and epidural anesthesia and to receive gentamicin as major antimicrobial prophylaxis. Blood and tissue samples were obtained concurrently at specific times throughout each procedure. The effect of intraoperative blood loss on gentamicin concentrations and its pharmacokinetic properties was determined. RESULTS: Sixteen patients completed the study (11 men, 5 women; white race, 16 patients [100%]; mean [SD] age, 61 [3] years [range, 39-80 years]). Mean (SEM) serum gentamicin concentration was found to be insufficient; the maximum plasma drug concentration/minimum inhibitory concentration (MIC) ratio was <8:1 for pathogens commonly isolated in the surgical unit of the hospital (MIC: 1-4 microg/mL). The mean (SEM) concentration at first surgical incision was 7.83 (0.82) microg/mL and decreased to 2.60 (0.28) microg/mL at skin closure, resulting in borderline effectiveness even for susceptible gram-positive microorganisms (MIC approximately 1.0). Initially, mean (SEM) tissue gentamicin concentrations in subcutaneous fat, epiploic fat, and colonic wall were low (2.02 [0.34] microg/mL, 2.41 [0.42] microg/mL, and 1.93 [0.38] microg/mL, respectively) and decreased approximately 1.0 microg/mL ( approximately 50%) by skin closure. Statistically significant positive correlations were found between gentamicin concentrations in serum and tissues (P 相似文献   

Evaluation of two prediction models for digoxin dosing

The relationship between the digoxin elimination parameter (A%) and creatinine clearance (CL_Cr) was determined, from blood level data of 160 hospital patients receiving digoxin tablets. The linear regression equation obtained, which varied only slightly from that reported by Jelliffe previously, was used to predict serum digoxin concentrations in 140 patients of four age groups (50–60, 60–70, 70–80 and 80–90 years). The predictions made were found to be less biased and more precise, irrespective of the age of the patients, than those produced using another predictive method known as Dobbs method. However, correlation coefficients of predicted versus measured serum digoxin concentrations for each method did not differ significantly and frequency distribution analyses of prediction errors gave poor results (up to 63% only). Therefore, neither method can be considered to be superior to the other nor can they be said to ensure accurate predictions of serum digoxin concentrations.